And Rojo was pictured on the plane from Portugal and again in Manchester as he prepares to become United's third major summer signing.

The 24-year-old had apologised to Sporting after refusing to train while the Portuguese club resolved their dispute with management company Doyen Sports, who owned some of Rojo's economic rights, before a fee was agreed.

United said on Twitter on Tuesday: "Manchester United is delighted to announce it has reached an agreement with Sporting Lisbon to sign defender Marcos Rojo, subject to a medical and agreeing personal terms. A further announcement will be made when the process is complete."

United, who have only signed Luke Shaw and Ander Herrera so far this summer, turned to Rojo after accepting defeat in their attempts to sign Mats Hummels and Thomas Vermaelen.

They have been short of defenders after the summer departures of Rio Ferdinand, Nemanja Vidic and Patrice Evra and manager Louis van Gaal's decision to switch to a formation that requires three centre-backs.

Shaw is out for four weeks with a hamstring injury and Van Gaal had to give 20-year-old Tyler Blackett a debut in the middle of defence in Saturday's defeat to Swansea so Rojo is likely to come straight into the team for Sunday's game at Sunderland.